First, I'm very new to ebooks. My only usage is a Literati that I got as a gift a few weeks ago and am enjoying very much.

I have written a 500+ page textbook in LaTeX on assembly language programming. It has over 100 figures (vector graphics), over 300 computer code listing, and many tables. It is beautifully formatted for a printed page.

This semester I decided to provide free pdf versions for the students. Many are using mobile readers. They are okay with the pdf, but they say it would be nice if the margins were smaller. I especially need to get rid of the gutter spacing (for double-sided printing).

The book is currently formatted for 8.5" X 11" pages. In another post pdurrant recommends 3.6" X 4.8" with 0.1" margins. Is this better than letting the ereader scale it?

Ultimately I may convert it to epub format, but with all the figures, code listings, etc., that will not be a trivial task. Meanwhile, I would like to improve what I have and get student feedback.

Welcome to MobileRead, rplantz - Very few ereaders do a good job of either scaling to fit or margin trimming (and the reflow option doesn't work for charts and such), so making the pfd fit a typical 6" diagonal screen is a good idea - that's the size pdurrant recommends. You'll probably have to redo your figures and tables to make them readable, though.

The book is currently formatted for 8.5" X 11" pages. In another post pdurrant recommends 3.6" X 4.8" with 0.1" margins. Is this better than letting the ereader scale it?

Let's assume you have it 8.5" × 11", with 1" margins, so the actual text block is 6.5" × 9"... with which font size? say it's around 12pt. Now this has to fit in a screen that, for a typical 6" reader, is around 3.6" × 4.8". Even if the reader could trim the margins and scale everything perfectly, it would be an almost 50% reduction, so the actual font size in the reader will be something like 7pt, which is probably too small, worse yet if you used some small type in your book.

If you format the book for 3.6" × 4.8" page size with 0.1" margins, still with 12pt font size, a 6" reader will happily display it in its original size or very slightly reduced, so the font will remain ~12pt. In a 5" reader, it could be shown at ~10pt, which is still fine.

Of course, you could also format the book for 8.5" × 11" pages, with 28pt font size, and it would look OK in a 6" screen. Or you could just scale down your 8.5" × 11", 12pt PDF to 3.6" × 4.8", and it would be pretty useless.